code: def test_forward():
      layer = LogMelFbank(n_fft=4, hop_length=1, n_mels=2)
      x = torch.randn(2, 4, 9)
      y, _ = layer(x, torch.LongTensor([4, 3]))
      assert y.shape == (2, 5, 9, 2)
  
file_path: espnet/test/espnet2/tts/feats_extract/test_log_mel_fbank.py
imports: import numpy
  import torch
  from espnet2.tts.feats_extract.log_mel_fbank import LogMelFbank
  from espnet.transform.spectrogram import logmelspectrogram
label_desc: Use image node_id 1 for calling a global function with example usage: test_forward() without return types